Numerical Study on the Influence of Material Characteristics on Ni-Ti Endodontic Instrument Performance

Abstract

Ni-Ti rotary endodontic instruments (files) are used in dentistry during the endodontic treatment to shape the root canal of the tooth while removing the pulp when infected. Up to now, the studies for evaluating their performances and drawbacks were mainly limited to experimental tests on product flexural and torsional resistance. This work exploits computational analyses for investigating the effects of materials with different mechanical properties on the behavior of rotary endodontic instruments. The aim is to understand the appropriate material choice to reduce the criticality of the treatment in particular clinical conditions. In particular, the interaction between an accurately modeled rotating file and differently shaped root canals during the clinical procedure was studied performing finite element analyses. Strains induced by the treatment on a file made of a ''standard'' Ni-Ti alloy (characterized by average properties of the pseudoelastic behavior), a ''long'' Ni-Ti alloy (characterized by wide transformation region), a ''super'' Ni-Ti alloy (characterized by an extended Hookian behavior without transformation region), and stainless steel were compared. The results accurately show the advantages of the use of Ni-Ti alloy with respect to stainless steel and the better performance of the ''long'' alloy in all the tested case.

Design Improvement and Failure Reduction of Endodontic Files through Finite Element Analysis: Application to V-Taper File Designs

“…They also investigated the influence of file material and root canal geometry on the strain profile. Their work was extended in another study (23) to include the effect of several NiTi material variants on the strain profile. Kim et al (24) and Kim et al (25) studied the effect of cross-section shape on the stress profile during simulated bending, torsion, and canal shaping by using full-length numerical model of commercial files.…”

Finite element analysis of rotary nickel‐titanium endodontic instruments: A critical review of the methodology

“…In terms of metallurgical properties, NiTi was compared against different alloys such as stainless steel, [17,27,28] ad-hoc designed NiTi alloys, [27] controlled-memory (CM) NiTi, [28] M-Wire, [21,[29][30][31][32]] fully R-phased NiTi, [32] gold-treated, [33,34] blue-treated NiTi [34] and theoretical alloys such as CuAlBe [35].…”

Methods and models to study nickel–titanium instruments

“…They investigated the influence of material and the root canal geometry on this strain profile. The work was extended in another study to include the effect of several NiTi materials on the strain profile.…”